There is the possibility that the operator misunderstands as if an abnormality has occurred in an apparatus, depending on the state of reception of an image changing in accordance with situation. This problem is solved by providing a reception unit for receiving images generated from a plurality of communication terminals, an output unit for outputting the images received by the reception unit in order to dipslay the images on a display unit as multiple images, and a notification unit for grasping and notifying a state of reception of the images by the reception unit.